Locking surgical tool handle system

ABSTRACT

A locking surgical tool handle system. The invention includes a surgical tool handle that has an elongated body portion with a pistol-type grip. The front end of the handle body has a tool retaining structure comprising a contoured engagement face and a movable tension bar with an engagement end. Projections on the engagement end of the tension bar fit within a receiving channel of a surgical tool, such as a broach or rasp. A locking mechanism is provided within the handle body, and is implemented with pivotable links attached to the tension bar. The locking mechanism has an unlocked position in which the engagement end of the tension bar is spaced away from the engagement face of the handle body, and an over-center locked position in which the engagement end of the tension bar is retracted toward the handle body. When the tool handle is placed in its locked position, the engagement end of the tension bar pulls an attached tool into tight contact with the engagement face of the handle body.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to surgical instruments, and more particularly toa locking surgical tool handle system.

2. Related Art

The use of prosthetic implants to replace the natural joints of a body,either as a result of disease or injury to the natural joint, isbecoming more and more commonplace. For example, in the replacement of ahip joint, it is very often necessary to replace the natural femoralhead with a prosthetic stem fixed within the femur and providing anaccurately located and securely held prosthetic head in place of thenatural femoral head. The prosthetic stem may by of a press-fit type, ora cemented type.

The procedure for implanting a prosthetic stem includes the use of abroach or rasp, usually as the last step in preparing the proximalfemoral shaft for the reception of the prosthetic stem. The purpose ofthe broach or rasp is to provide contouring of the proximal femoralshaft to the gross geometry of the prosthetic stem, thereby assuringaccurate location and good fit. The configuration of the broach or raspis made to emulate that of the prosthetic stem (and its cement mantle,when used) to enable the attainment of the desired stem shape.

In order to facilitate utilization of such a broach or rasp, it has beensuggested that the handle of the instrument be selectively detachablefrom the instrument tool so that the location of the tool within thefemoral shaft can be gauged precisely and used as a means of determiningthe subsequent location of the prosthetic stem. Further, if the handleis detachable, the tool may be used for location of a trial neckattachment to assure that the length of the reconstructed prosthesis isaccurate, and for milling of the femoral calcar (through an opening inthe tool) to assure that the bone surface is flat and in line with theface of the tool.

A number of handles for use with releasable broaches or rasps have beenproposed in the past. Examples are given in U.S. Pat. Nos. 4,306,550;4,583,270; 4,587,964; 4,601,289; and 4,765,328. However, these existinghandles exhibit a number of problems. Several fail to achieve a tightfit between the tool and handle. A tight fit is necessary to permit goodcontrol of the tool during a surgical procedure. Many of the existinghandles suffer a high rate of failure between the attachment peg orother interfacial locking component between the handle and tool. A fewof the existing designs simply cannot withstand repeated impactsnecessary during insertion and removal of a broach or rasp. Lastly, anumber of the designs are non-ergonomic, which makes use difficultduring a surgical procedure.

It is therefore desirable to provide an ergonomic handle that attachesto cutting tools used during surgery, and in particular, that attachesto rasps and broaches used to fashion the intramedullary canal of thefemur during a hip replacement procedure. It is also desirable toprovide a design that incorporates proper balance, rigid construction,secure locking of a tool to the handle, quick release to facilitateusage during surgery, and rugged design that survives through repeatedimpacts during insertion and removal of a tool in surgery.

The present invention provides a locking surgical tool handle that meetsthese goals.

SUMMARY OF THE INVENTION

The invention includes a surgical tool handle that has an elongated bodyportion with a pistol-type grip. The front end of the handle body has atool retaining structure comprising a contoured engagement face and amovable tension bar with an engagement end. Projections on theengagement end of the tension bar fit within a receiving channel of asurgical tool, such as a broach or rasp.

A locking mechanism is provided within the handle body, and isimplemented with pivotable links attached to the tension bar. Thelocking mechanism has an unlocked position in which the engagement endof the tension bar is spaced away from the engagement face of the handlebody, and an over-center locked position in which the engagement end ofthe tension bar is retracted toward the handle body. When the toolhandle is placed in its locked position, the engagement end of thetension bar pulls an attached tool into tight contact with theengagement face of the handle body.

The present invention provides a surgical tool coupling system whichenables effective selective attachment and detachment of a surgical toolfrom the tool handle. The design of the preferred embodiment exhibitsstrength and rigidity in the connection between a tool and a handle foraccuracy and precision in the use of the tool; ease of attachment ordetachment of the tool, for facilitating the use of the detachablehandle feature under the conditions encountered during a surgicalprocedure, and, in particular, enabling quick and reliable attachment ordetachment under operating room conditions; simplicity in the number andconfiguration of the component parts of the tool handle, enabling easeof maintenance as well as use; compliance with all the requirements forsurgical instruments insofar as materials and construction necessary toserve in a surgical environment; and a rugged construction for reliableservice over an extended service life.

The details of the preferred embodiment of the present invention are setforth in the accompanying drawings and the description below. Once thedetails of the invention are known, numerous additional innovations andchanges will become obvious to one skilled in the art.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional side view of the surgical tool handle, shownin its locked position with a tool attached.

FIG. 2 is a top view of the surgical tool handle, shown in its lockedposition.

FIG. 2a is a top view of the front end of the surgical tool handle,shown in its unlocked position.

FIG. 3 is an end view of a tool used in conjunction with the surgicaltool handle.

FIG. 4 is a cross-sectional side view of the surgical tool handle, shownin its unlocked position, juxtaposed to the engagement end of a tool.

Like reference numbers and designations in the drawings refer to likeelements.

DETAILED DESCRIPTION OF THE INVENTION

Throughout this description, the preferred embodiment and examples shownshould be considered as exemplars, rather than limitations on thestructure of the present invention.

FIG. 1 shows a cross-sectional side view of the inventive surgical toolhandle 1 with a tool 2 attached. The tool handle 1 includes an elongatedhandle body 3 having a hollow front barrel 4 and a rear lock housing 5.The barrel 4 may be attached to the lock housing 5 by means of athreaded coupling, or two elements may be constructed as a unitarystructure. The front end of the barrel 4 is affixed to an engagementface 6, which is contoured to fit closely to a corresponding mating face7 of the tool 2.

The handle body 3 has an insertion striking plate 8 on one end, toreceive impacts from a surgical mallet and transmit the impact forcesdown the axis of the handle body 3 to the attached tool 2. The design ofthe present invention permits the transmittal of impacts on theinsertion strike plate 8 to be directly transmitted to the tool 2through the contacting engagement face 6 and tool mating face 7 withoutbeing transmitted through the fastening structure.

Situated within the handle body 3 is a tension bar 9, which is slidablewithin the interior of the handle body 3. An engagement end 10 of thetension bar 9 projects through the engagement face 6 of the barrel 4.The engagement end 10 of the tension bar 9 is formed with at least oneengagement projection 11 (see FIG. 2a) projecting approximatelyperpendicular to the longitudinal axis of the tension bar 9. In thepreferred embodiment, the engagement projections 11 are formed from dualbars extending perpendicular to the tension bar 9, causing theengagement end 10 of the tension bar 9 to have a "T"-shapedconfiguration.

The engagement face 6 of the preferred embodiment of the invention mayinclude a boss 12 at one edge of the engagement face 6 (see FIG. 4). Theboss 12 mates with a matching indentation 13 in the tool 2 (see FIG. 3),and serves as a stop that prevents sliding movement and inhibitsrotation of the tool 2 with respect to the engagement face 6, once thetool 2 is pulled into locking engagement by retraction of the tensionbar 9.

As noted above, the tool 2 has a mating face 7 configured to closely fitthe engagement face 6 of the handle body 3. Formed into the attachmentend 14 of the tool 2 is a channel 15 configured to be engaged by theengagement projections 11 of the tension bar 9 (see also FIG. 3). In thepreferred embodiment, the channel 15 is "L"-shaped when viewed from theside, such that the "T"-shaped engagement projections 11 enter into thechannel opening and are then positioned up into a channel recess 15a,which may include a detent 15b.

The other end of the tension bar 9 is coupled to a locking mechanismwhich comprises an upper link 16 and a lower link 17. The upper link 16is pivotally coupled to the lock housing 5 at a housing pivot 16a. Theupper link 16 also has a lock handle 18 for ease of use. The lower link17 is pivotally coupled to the tension bar 9 at a tension bar pivot 17a,and to the upper link 16 at a link pivot 17b.

The tool handle 1 also includes a hand grip 19 for holding the toolhandle 1. The grip 19 is preferably mounted at a comfortable angle withrespect to the handle body 3. In the preferred embodiment, the angle isapproximately 90°, but other angles may be chosen if desired. In thepreferred embodiment, the grip 19 is directly attached to the tensionbar 9. An opening 20 in the lock housing 5 permits the grip 19 to slidewith the tension bar 9 as the tension bar 9 moves from its unlockedposition to its locked position.

A removal striking plate 21 is mounted on the grip 19 such that the faceof the striking plate 21 is perpendicular to the handle body 3. Theremoval striking plate 21 serves as a striking surface aligned along theaxis of the handle body 3, which permits transmittal of striking impactsfrom a surgical mallet parallel to that axis. Because of the directconnection between the grip 19 and the tension bar 9, impacts made onthe removal striking plate 21 are directly imparted to the tension bar9, and thus directly to an attached tool 2 through the engagement end10. This permits a surgeon to remove a tool from a femur, for example,in a straight line fashion, rather than at an angle to the bone.

As shown in FIGS. 1 and 4, the locking handle 18 has two positions. Inthe locked position shown in FIG. 1, the link pivot 17b is in-line withthe housing pivot 16a and the tension bar pivot 17a. This position ofthe link pivot 17b maximizes the distance between the housing pivot 16aand the tension bar pivot 17a, and creates the greatest effective lengthfor the lower link 17. If the link pivot 17b is moved off of the linebetween the housing pivot 16a and the tension bar pivot 17a, theeffective length of the lower link 17 is decreased.

When a tool 2 is situated such that the engagement projections 11 arewithin the detent 15b of the channel recess 15a of a tool 2, moving thelock handle 18 into its locked position increases the effective lengthof the lower link 17. The tension bar pivot 17a end of the lower link 17is forced towards the rear of the tool handle 1, pulling the tension bar9 backwards into the tool handle 1. The tension bar 9 therefore pullsthe tool 2 into tight contact against the engagement face 6 and the boss12 of the tool handle 1. In the preferred embodiment of the invention,the lock mechanism in its locked position is in a stable, self-retaining"over-center" position. Therefore, the lock handle 18 will not move fromits locked position without the application of sufficient force to movethe lock handle 18 past its center position.

In the unlocked position shown in FIG. 4, the lock handle 18 is raisedout from the lock housing 5, pivoting the upper link 16 around thehousing pivot 16a. The link pivot 17b end of the lower link 17 is movedoff of the line between the housing pivot 16a and the tension bar pivot17a, thereby decreasing the effective length of the lower link 17. Thelower link 17 pulls the tension bar pivot 17a forward toward the frontend of the tool handle 1. This change in geometry of the lower link 17with respect to the upper link 16 pushes the tension bar 9 forwardwithin the barrel 4 of the tool handle 1. The engagement projections 11of the tension bar 9 are thus moved away from the engagement face 6 ofthe tool handle 1. The tool 2 may then be disengaged from the engagementprojections 11 by moving the engagement projections 11 out of thechannel recess 15a and through the opening of the channel 15.

The locking mechanism thus provides a quick and easy means of attachingor detaching a tool 2 from the tool handle 1. The invention is simple inconstruction, and is preferably completely made of metal (for example,stainless steel) to make sterilization easier in a medical setting.

A number of embodiments of the present invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention. Forexample, the shape of the engagement projections 11 can be changed asdesired, and can include a hook-like or disk-shaped projection, so longas the engagement projections 11 can engage a tool 2 such that tensionprovided by the locked tension bar 9 pulls the tool 2 into tight contactwith the engagement face 6. Similarly, the channel 15 of the tool 2 canbe formed in various shapes and orientations, so long as the engagementprojections 11 can engage the tool 2 securely. Further, the tension bar9 could be replaced by a flexible tension element, such as a wire cable,since the principal function of the tension bar 9 is to pull a tool 2tightly against the engagement face 6 of the tool handle 1. Furtherstill, the tool 2 can be of any type, and is not limited to broaches orrasps used for hip replacement surgery.

Accordingly, it is to be understood that the invention is not to belimited by the specific illustrated embodiment, but only by the scope ofthe appended claims.

We claim:
 1. A locking surgical tool handle system, comprising:a. a toolfor at least one of cutting, shaping, and forming biologic tissues, thetool having a flanged recess for receiving at least one engagementprojection; b. a tool handle, including:(1) a body having an engagementend and a hollow shaft disposed within the body; (2) a tension elementdisposed within the shaft of the body, the tension element extending outfrom the engagement end of the body and having at least one engagementprojection for engaging the flanges of the recess of the tool; (3) ahand grip attached to the tension element; (4) locking means, coupled tothe tension element, for pulling the tension element into a lockedposition within the body when at least one engagement projection isdisposed within the recess of the tool, the locking means including:(a)a first link coupled to the tension element by a tension element pivot;(b) a second link coupled to the first link by a link pivot, and coupledto the tool handle body by a body pivot; (c) the locking means having(1) an over-center locked position in which the link pivot is in-linewith the body pivot and the tension element pivot, and the distancebetween the body pivot and the tension element pivot has a first length,and (2) an unlocked position in which the link pivot is not in-line withthe body pivot and the tension element pivot, and the distance betweenthe body pivot and the tension element pivot has a second length shorterthan the first length;whereby the tool is held to the engagement end ofthe tool handle by the application of tension to the tool by the tensionelement when the locking means is in its locked position, thuspermitting the tool to perform at least one of cutting, shaping, andforming biologic tissues.
 2. The locking surgical tool handle system ofclaim 1, further including an insertion striking plate attached to thetool handle body, along the longitudinal axis thereof, and opposite theengagement end of the body.
 3. The locking surgical tool handle systemof claim 1, further including a removal striking plate attached to thehand grip, and having a striking face perpendicular to the longitudinalaxis of the tool handle body.
 4. The locking surgical tool handle systemof claim 1, wherein the engagement projection of the tension element is"T"-shaped.
 5. The locking surgical tool handle system of claim 1,wherein the recess of the tool is "L"-shaped.
 6. The locking surgicaltool handle system of claim 1, further including a boss on theengagement end of the body and a matching indentation on the tool, forpreventing sliding movement of the tool with respect to the engagementend of the body.
 7. A locking surgical tool handle, for use with a toolfor at least one of cutting, shaping, and forming biologic tissues, thetool having a flanged recess for receiving at least one engagementprojection, the tool handle including:a. a body having an engagement endand a hollow shaft disposed within the body; b. a tension elementdisposed within the shaft of the body, the tension element extending outfrom the engagement end of the body and having at least one engagementprojection for engaging the flanges of the recess of a tool; c. a handgrip attached to the tension element; d. locking means, coupled to thetension element, for pulling the tension element into a locked positionwithin the body when at least one engagement projection is disposedwithin the recess of the tool, the locking means including:(1) a firstlink coupled to the tension element by a tension element pivot; (2) asecond link coupled to the first link by a link pivot, and coupled tothe tool handle body by a body pivot; (3) the locking means having (1)an over-center locked position in which the link pivot is in-line withthe body pivot and the tension element pivot, and the distance betweenthe body pivot and the tension element pivot has a first length, and (2)an unlocked position in which the link pivot is not in-line with thebody pivot and the tension element pivot, and the distance between thebody pivot and the tension element pivot has a second length shorterthan the first length;whereby the tool is held to the engagement end ofthe tool handle by the application of tension to the tool by the tensionelement when the locking means is in its locked position, thuspermitting the tool to perform at least one of cutting, shaping, andforming biologic tissues.
 8. The locking surgical tool handle of claim7, further including an insertion striking plate attached to the toolhandle body, along the longitudinal axis thereof, and opposite theengagement end of the body.
 9. The locking surgical tool handle of claim7, further including a removal striking plate attached to the hand grip,and having a striking face perpendicular to the longitudinal axis of thetool handle body.
 10. The locking surgical tool handle of claim 7,wherein the engagement projection of the tension element is "T"-shaped.11. The locking surgical tool handle of claim 7, wherein the recess ofthe tool is "L"-shaped.
 12. The locking surgical tool handle of claim 7,wherein the tool has an indentation, and further including a matchingboss on the engagement end of the body, for preventing sliding movementof the tool with respect to the engagement end of the body.
 13. Alocking surgical tool handle, for use with a tool for at least one ofcutting shaping and forming biologic tissues, the tool having an"L"-shaped recess for receiving at least one engagement projection, thetool handle including:a. a body having an engagement end and a hollowshaft disposed within the body; b. an insertion striking plate attachedto the tool handle body, along the longitudinal axis thereof, andopposite the engagement end of the body; c. a tension element disposedwithin the shaft of the body, the tension element extending out from theengagement end of the body and having a "T"-shaped engagement projectionfor engaging the recess of the tool; d. a hand grip attached to thetension element; e. a removal striking plate attached to the hand grip;f. locking means, coupled to the tension element, for pulling thetension element into a locked position within the body when at least oneengagement projection is disposed within the recess of a tool, thelocking means including:(1) a first link coupled to the tension elementby tension element pivot; (2) a second link coupled to the first link bya link pivot, and coupled to the tool handle body by a body pivot; (3)the locking means having (1) an over-center locked position in which thelink pivot is in-line with the body pivot and the tension element pivot,and the distance between the body pivot and the tension element pivothas a first length, and (2) an unlocked position in which the link pivotis not in-line with the body pivot and the tension element pivot, andthe distance between the body pivot and the tension element pivot has asecond length shorter than the first length; whereby the tool is held tothe engagement end of the tool handle by the application of tension tothe tool by the tension element when the locking means is in its lockedposition, thus permitting the tool to perform at least one of cutting,shaping, and forming biologic tissues.